"Today, I am declaring my independence and leaving the Republican Party," Amash wrote in the Washington Post opinion piece. "No matter your circumstance, I’m asking you to join me in rejecting the partisan loyalties and rhetoric that divide and dehumanize us. I’m asking you to believe that we can do better than this two-party system — and to work toward it. If we continue to take America for granted, we will lose it."

Amash’s decision has already sparked days of political fallout, but Congress's return from the July 4th recess is prompting additional questions, including the future of his membership in the House Republican Conference and his committee assignments.

“Amash left the @freedomcaucus now he’s leaving the @GOP. The @HouseGOP never left @justinamash - we simply ran out of space for his ego. However, we should make sure he leaves Conference and his committee,” Walker tweeted following Amash’s announcement of his decision to leave the GOP.

A two-thirds vote within the House GOP conference would be required to expel him from conferencing with the party. House Republicans are likely to meet as a caucus on Wednesday for the first time since Amash’s announcement.

It remains unclear what will happen to his committee assignments in the wake of his decision.

“I anticipate I may be kicked off [the House Oversight and Reform Committee]. … I've tried to make changes from within. … I have colleagues trying every day, but they are not speaking out the same way. I hope they will speak out,” he told CNN on Sunday.

President Trump praised his decision to exit the Republican party, blasting him as one of the “dumbest & most disloyal men in Congress.”

“Great news for the Republican Party as one of the dumbest & most disloyal men in Congress is ‘quitting’ the Party. No Collusion, No Obstruction! Knew he couldn’t get the nomination to run again in the Great State of Michigan. Already being challenged for his seat. A total loser!” he tweeted.

Amash’s decision to exit the party while in office is highly unusual.

"Amash is the first Republican House member in 20 years to leave the GOP," Antoine Yoshinaka, a political science professor at the New York State University at Buffalo, told USA Today.

The publication also notes that Amash is the third Republican lawmaker to leave the party since 2000, along with then-GOP Sens. Arlen Specter (Pa.) and Jim Jeffords (Vt.).

Amash’s decision to leave the party paves the way for Republicans, including the National Republican Campaign Committee, to back a GOP challenger to try to unseat him next year.

Top Republicans had already stated that they expected a well-funded primary challenge against the Michigan libertarian after his impeachment remarks earlier this year.

But Amash said Sunday that "high-level" Republican officials have praised his remarks on impeachment, and that he isn’t concerned about facing a pro-Trump challenger in the race for his seat.

"When I go back to my district people are coming up to me and saying, 'Thank you for what you're doing,'" he said during an appearance on CNN’s State of the Union. "People want open, honest representation. They want people to come to Congress and work with integrity."

Amash has also not ruled out launching a presidential bid against Trump in 2020.

"I still wouldn't rule anything like that out. I believe that I have to use my skills, my public influence, where it serves the country best. And I believe I have to defend the Constitution in whichever way works best," he told CNN.

The potential bid has some within the GOP concerned it could hurt the president’s chances of winning key states.

The House Committee on Oversight and Reform will also hold a hearing Wednesday on the administration’s stance on Texas v. United States, including the decision to back striking down the entire 2010 Affordable Care Act.

The 5th Circuit Court of Appeals in New Orleans will hear arguments on Tuesday on the lawsuit to nix the law, a lawsuit which is backed by the Trump administration.

Though legal experts say the lawsuit is unlikely to ultimately succeed, the outcome isn’t guaranteed, and Democrats are using it to argue Republicans are a threat to the 20 million people who rely on ObamaCare for health insurance.

Defense authorization

The House is poised to take up a massive defense bill that could allow Democrats to push back on elements of Trump’s defense and foreign policy.

The $733 billion National Defense Authorization Act (NDAA) provides funding and broad policy guidelines for the Pentagon for the 2020 fiscal year, which starts in October.

The House bill prohibits Pentagon funding from being used on the border wall, makes changes to the emergency authority Trump invoked to dip into Pentagon coffers for the wall and modifies the authority Trump has used to deploy U.S. troops to the border.

House Democrats are also expected to incorporate an amendment that would prevent Trump from taking military action against Iran without congressional approval. The Senate rejected a similar amendment in a 50-40 vote before the July 4th recess.

Once the House passes its bill it will need to be reconciled with the Senate legislation, which passed that chamber last month. While the Senate’s bill was largely bipartisan, the House Armed Services Committee passed its bill largely along party lines.

The House Judiciary Committee will hold a hearing on Friday morning entitled “Constitutional Processes for Addressing Presidential Misconduct.”

Mueller, in his final report, did not reach a conclusion on whether Trump obstructed justice, saying he was precluded from doing so by a Justice Department opinion that says a sitting president cannot be indicted. Instead, he outlined 10 “episodes” of possible obstructive behavior regarding ongoing probes into Russia's election meddling.

Republicans have prioritized circuit court picks and have viewed the Ninth Circuit as a perennial annoyance, arguing that it’s too large and too liberal.

With only a simple majority needed for confirmation and Republicans holding a 53-47 Senate majority, Bress is expected to be confirmed, even though neither Feinstein nor Harris returned their blue slip for him.

Feinstein and Harris said in a statement last month that Bress was a Washington, D.C., lawyer and not involved in California's legal community.

“He attended law school and clerked for two federal judges on the East Coast. Apart from being admitted to practice in California, he’s not involved in any of the state’s legal or civic organizations and hasn’t been a member of the California legal community,” the two said in a statement.

The "blue-slip" rule — a precedent upheld by Senate tradition — has historically allowed a home-state senator to stop a lower-court nominee by refusing to return the blue slip to the Judiciary Committee. How strictly the precedent is upheld is decided by the committee chairman, and enforcement has varied depending on who wields the gavel.

Though Republicans say they will honor blue slips for lower-court district nominees, whose rulings can be overruled by circuit courts, they have moved several circuit nominations over the objection of Democratic home-state senators.